Minimally invasive mitral valve surgery: a review of the literature

Purpose

Minimally invasive mitral valve surgery (MIMVS) is a heterogenous concept referring to a gamut of surgical approaches to the mitral valve. When compared to conventional sternotomy (CONV-ST), MIMVS appears to offer superior patient satisfaction and recovery time. However, published results differ between institutions due to variations in technique, and mid- to long-term data is relatively scant. Despite the limitations of the evidence base, patient demand for minimally invasive operations remains strong. This demand is only likely to rise in the future as surgery is being recommended earlier in the course of disease and patients are referred for operation at a younger age. This review therefore isolates each MIMVS technique to evaluate its place in current surgical practice, as well as areas of future research.

Methods

A comprehensive literature search was performed using MEDLINE, Embase, Google Scholar, and Scopus. Search terms included ‘minimally invasive surgical procedures’, ‘mitral valve’, ‘sternotomy’, ‘thoracotomy’, ‘mitral valve repair’, and ‘mitral valve replacement’. Articles were also gathered from other sources, including manual searches through reference lists of articles and recommended ‘related articles’.

Summary

MIMVS has evolved from using smaller incisions to endoscopic surgery, robotics, and, most recently, percutaneous off-pump procedures. It is now standard practice at centres around the world. At present, the right minithoracotomy is the most common approach, though robotic and percutaneous techniques are suitable for certain patients. Collaboration between cardiothoracic surgeons, interventional cardiologists, and other disciplines will be essential in furthering the newest minimally invasive techniques. Future research should depend on long-term data, broad patient sampling, and high-tier evidence.

     

Different ways to repair the mitral valve with artificial chordae: a systematic review

Myxomatous mitral regurgitation (type II Carpentier's functional classification) affects about 1-2% of the population. This represents a very common indication for valve surgery resulting in a low percentage of repairs compared to replacement which is actually performed. In the last decades, several methods for mitral valve repair have been developed, to make the surgical feasibility easier, improve the long-term follow-up thus avoiding the need for reoperations. A very interesting method is represented by the combination of various valve repair techniques, depending on the involvement of the anterior, posterior, or both leaflets, and the use of PTFE artificial chordae tendineae when excessive chordal elongation or rupture due to myxomatous degeneration co-exists. The aim of this review is to summarize the evolution of these techniques from the beginning till now.     

Double orifice mitral valve: a case report and review of management.

This paper reports a case of double orifice mitral valve which was treated conservatively. A new scheme of classification of this entity linked to the accepted lines of surgical treatment is introduced.     

Orthotopic liver transplantation without bypass in a patient with mitral valve prolapse

Editor—Orthotopic liver transplantations (OLT) withoutbypass are associated with the potential for significant bloodloss, sharply decreasing intravascular volume during anhepaticstage, aggressive overloaded volume on reperfusion, and developedreperfusion syndrome around the time of reperfusion. A featureof mitral valve prolapse (MVP) is mitral regurgitation (MR)which may be exacerbated by increased systemic vascular resistance(SVR), bradycardia or excessive tachycardia, and volume overload.We present a case of a successful OLT without bypass in a patientwith anatomical MVP associated with moderate MR with a historyof end-stage liver disease. We present the anaesthetic problemsand management for this     

Ex-vivo mitral valve repair prior to orthotopic cardiac transplantation

Mitral valve annuloplasty was performed prior to orthotopic cardiac transplantation in two donor hearts which were diagnosed with moderate to severe mitral regurgitation. The technical aspects are reviewed of ex-vivo mitral valve repair with concomitant heart transplantation. The recipients were classified as United Network for Organ Sharing (UNOS) I and both patients have had an excellent postoperative recovery. Over 2-year follow-up demonstrates normal mitral valve function without regurgitation.     

Aneurysm of the mitral valve: a rare complication of aortic valve endocarditis

A 45-year-old man presented to our hospital with severe dyspnea 4 months after antibiotic treatment for aortic valve endocarditis. Transesophageal echocardiography revealed severe aortic regurgitation and an aneurysm of the anterior leaflet of the mitral valve. In addition to aortic valve replacement, we excised the aneurysm and repaired the anterior leaflet of the mitral valve. Clinical suspicion, appropriate preoperative imaging, and timely surgical intervention are essential to recognize and treat this rare complication of bacterial endocarditis.     

Valve replacement for congenital mitral stenosis associated with double orifice mitral valve: a case report and a review of Japanese literatures

A 3-year-old girl with congenital mitral stenosis (CMS) associated with double mitral orifice valve (DOMV) underwent successfully mitral valve replacement (MVR). DOMV is a rare form of congenital cardiovascular anomaly. To our knowledge, our patient is the first infant case of CMS due to DOMV in Japan. We present an infant case of CMS associated with DOMV who needed MVR, and discuss our patient with a review of Japanese literatures.     

A comparison of mitral valve reconstruction with mitral valve replacement: intermediate-term results

The continued good results after mitral valve reconstruction prompted this retrospective study to compare operative and late results from our institutional experience since 1976 with 975 porcine mitral valve replacements (MVRs) (1976 to December 1987), 169 mechanical MVRs (1976 to December 1987), and 280 Carpentier-type mitral valve reconstructions (CVRs) (1980 to mid-1988). The operative mortality was 2.0% for isolated CVR, 6.6% for isolated mechanical MVR, and 8.5% for isolated porcine MVR. The overall operative mortality was 5.0% for CVR, 16.6% for mechanical MVR, and 10.6% for porcine MVR. The overall 5-year survival including hospital deaths was 76% for CVR, 72% for mechanical MVR, and 69% for porcine MVR. By multivariate analysis, the predictors of increased operative risk and of decreased survival were age, New York Heart Association functional class IV status, previous cardiac operation, and performance of concomitant cardiac surgical procedures. The type of valvular procedure was not predictive of operative risk or overall survival. The 5-year freedom from reoperation was 94.4% for nonrheumatic patients having CVR, 77.4% for rheumatic patients having CVR, 96.4% for mechanical MVR, and 96.6% for porcine MVR (p less than 0.05, rheumatic patients with CVR versus both MVR groups). The 5-year freedom from all valve-related morbidity and mortality was significantly better for valve reconstruction compared with both types of valve replacement. Thus, the operative risk and late survival obtained after mitral valve reconstruction were at least equivalent to those obtained after MVR. In addition, patients receiving mitral valve reconstruction had less valve-related combined morbidity than patients receiving valve replacement, thus making mitral valve reconstruction preferable in some patients with mitral insufficiency.     

Homologous meniscus transplantation

Summary The increase in severe ligament injuries of the knee has led to consideration of the need for meniscal transplantation in reconstructive operations for chronic rotational instability. Transplantation of the medial meniscus was carried out in two groups of 15 sheep. In one group lyophilised, -sterilised allogenic menisci were transplanted and these underwent a complete remodelling in 48 weeks. In the other group, deep frozen allogenic menisci were used and these remained fully functional without remodelling. We then carried out meniscal transplantation in 22 patients who were followed-up for a mean of 14 months. Arthroscopy was possible in two-thirds of the cases at an average of 8 months after operation. Both types of transplanted menisci, lyophilised and deep frozen, decreased in size, as small as a regenerated meniscus in some cases. In general the deep frozen menisci showed better results.

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Résumé L'augmentation de fréquence des graves traumatismes ligamentaires du genou a conduit à envisager la transplantation méniscale dans les opérations reconstructrices pour instabilité rotatoire chronique. La transplantation du ménisque interne a été réalisée dans deux groupes de 15 moutons. Dans un groupe on a utilisé des ménisques allogènes lyophylisés et stérilisés aux rayons , qui ont présenté, à la 48ème semaine, une transformation complète. Dans l'autre groupe, on a transplanté des ménisques allogènes réfrigérés à –30° C et ceuxci sont restés parfaitement fonctionnels, sans transformation. Nous avons réalisé une transplantation méniscale chez 22 malades, qui ont eté suivis 14 mois en moyenne. Dans les deux-tiers des cas une arthroscopie a été possible vers le 8ème mois après l'opération. Les deux types de ménisques, lyophylisés et réfrigérés, diminuent de volume pour devenir aussi grêles, dans quelques cas, qu'un ménisque régénéré. Dans l'ensemble les ménisques conservés au froid donnent les meilleurs résultats.

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This work received the Müller-SICOT award in 1987